The present invention relates to a handheld grinding device. The invention is particularly useful as a dental tool for crown preparation, and is therefore described below with respect to this application, although it will be appreciated that the invention could also advantageously be used in other applications.
Preparation of a crown usually requires grinding the tooth enamel to the sub-gingival margin, particularly in the preparation of frontal upper teeth for porcelain crowns. Grinding the tooth at the sub-gingival margin, however, frequently causes damage to the adjacent gingival tissue. Such damage not only results in considerable patient discomfort, but can also cause irreversible gingival retraction and local edema. The latter, when it occurs, often forces the dentist to postpone continuation of the treatment, e.g. of taking impressions for working models, until the area heals.
A small percentage of dentists use guards for protecting the gingival during grinding of the tooth for crown preparation. However, such guards are difficult to set in place, and often become dislodged. Moreover, using them is very time-consuming, particularly since they must be reset each time the dentist wishes to prepare another tooth. Further, the known guards provide, at best, very limited protection. These drawbacks stem, in large part, from the static nature of the guard; and because of these problems, most dentists do not use any protection whatsoever.